MAX17681

4.5V to 42V Input, High-Efficiency, Iso-Buck DC-DC Converter

Reduces External Components and Cost for DC-DC Isolation


Please check latest availability status for a specific part variant.

Description

The MAX17681/MAX17681A is a high-voltage, high-efficiency, iso-buck DC-DC converter designed to provide isolated power up to 5W. The device operates over a wide 4.5V to 42V input and uses primary-side feedback to regulate the output voltage.

MAX17681/MAX17681A uses peak-current-mode control. The low-resistance, on-chip MOSFETs ensure high efficiency at full load while simplifying the PCB layout.

The MAX17681/MAX17681A devices generate a well regulated primary side voltage which is then scaled by a suitable transformer turns ratio to derive isolated secondary output rails. While both MAX17681 and MAX17681A support primary side overcurrent protection, the MAX17681A is an enhanced design that supports robust secondary-side overcurrent protection as well.

The MAX17681/MAX17681A is available in a compact 10-pin (3mm x 2mm) TDFN package. Simulation models are available.

MAX17681: Application Circuit MAX17681: Application Circuit Enlarge+

Key Features

  • Reduces External Components and Total Cost
    • No OptoCoupler
    • Synchronous Primary Operation
    • All-Ceramic Capacitors, Compact Layout
  • Reduces Number of DC-DC Regulators to Stock
    • Wide 4.5V to 42V Input
    • 0.9V to 0.96 x VIN Primary Output Voltage
    • Delivers Up to 5W Output Power
  • Reduces Power Dissipation
    • Peak Efficiency > 90%
    • 0.9µA (typ) Shutdown Current
  • Operates Reliably in Adverse Industrial Environments
    • Peak and Sink Current-Limit Protection
    • ±1.7% Feedback Accuracy
    • Programmable EN/UVLO Threshold
    • Adjustable Soft-Start
    • Overtemperature Protection
    • -40°C to +125°C Operation
  • Short-Circuit Protection
    • MAX17681A Supports Robust Secondary-Side Short-Circuit Protection
    • MAX17681A Is Recommended for All New Designs

Applications/Uses

  • Floating Power Supply Generation
  • Isolated Fieldbus Interfaces
  • Isolated Power Supplies in Medical Equipment
  • PLC I/O Modules
  • Smart Meters
Part Number Application (VIN) VIN
(V)
VIN
(V)
Topology Switch Type Feedback Freq.
(kHz)
Duty Cycle
(%)
ISTARTUP
(mA)
ICC
(mA)
Oper. Temp.
(°C)
Package/Pins Budgetary
Price
min max max max max See Notes
MAX17681 
Base Station (24V)
Industrial (24V)
4.5 42 Flyback Internal Primary Side 200 97.5 2.8 2.8 -40 to +125
TDFN/10
$1.40 @1k
See All Isolated Power Supplies (24)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.


MAX17681EVKIT: Evaluation Kit for MAX17681 Isolated ±15V or ±12V Output Configuration
MAX17681EVKITC: Evaluation Kit for the MAX17681 Isolated +15V or +12V Output Configuration
MAX17681EVKITD: Evaluation Kit for the MAX17681 Isolated +7V or +5V Output Configuration
MAX17681EVKITF: Evaluation Kit for the MAX17681 Isolated +24V Output Configuration
MAX17681EVKITB: Evaluation Kit for the MAX17681 Isolated ±7V or ±5V Output Configuration
MAX17681EVKITE: Evaluation Kit for MAX17681 Isolated ±15V and ±7.5V Output Configuration
MAX17681AEVKITA: Evaluation Kit MAX17681A for Isolated ±15V or ±12V Output Configuration
MAX17681AEVKITB: Evaluation Kit MAX17681A for Isolated ±7V or ±5V Output Configuration
MAX17681AEVKITE: Evaluation Kit MAX17681A for Isolated ±15V and ±7.5V Output Configuration
MAX17681AEVKITF: Evaluation Kit MAX17681A for Isolated +24V Output Configuration
MAX17681AEVKITD: Evaluation Kit MAX17681A for Isolated +7V or +5V Output Configuration
MAX17681AEVKITC: Evaluation Kit MAX17681A for Isolated +15V or +12V Output Configuration

Technical Documents

Brochure 6362 Powering the Pocket IO PLC Development Platform
User Guide 5861 EE-SIM Design and Simulation Environment User Guide

Quality and Environmental Data

Product Reliability Reports: MAX17681.pdf 
Lead-Free Package Tin (Sn) Whisker Reports

Additional Resources

Download SIMPLIS model ›
Topmark Coding MAX17681
Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

Quality Management System >
Environmental Management System >

Related Resources

Type ID Title
System Board6692MAXREFDES1170: 24V/100mA, Iso-Buck DC-DC Converter Using the MAX17681A
System Board6330MAXREFDES150#: Pocket IO PLC Development Platform
Evaluation Board9476MAX17681AEVKITC Evaluation Kit MAX17681A for Isolated +15V or +12V Output Configuration
Evaluation Board9475MAX17681AEVKITD Evaluation Kit MAX17681A for Isolated +7V or +5V Output Configuration
Evaluation Board9471MAX17681AEVKITF Evaluation Kit MAX17681A for Isolated +24V Output Configuration
Evaluation Board9470MAX17681AEVKITE Evaluation Kit MAX17681A for Isolated ±15V and ±7.5V Output Configuration
Evaluation Board9466MAX17681AEVKITB Evaluation Kit MAX17681A for Isolated ±7V or ±5V Output Configuration
Evaluation Board9462MAX17681AEVKITA Evaluation Kit MAX17681A for Isolated ±15V or ±12V Output Configuration
Evaluation Board9053MAX17681EVKITE Evaluation Kit for MAX17681 Isolated ±15V and ±7.5V Output Configuration
Evaluation Board9028MAX17681EVKITB Evaluation Kit for the MAX17681 Isolated ±7V or ±5V Output Configuration
Evaluation Board9022MAX17681EVKITF Evaluation Kit for the MAX17681 Isolated +24V Output Configuration
Evaluation Board9021MAX17681EVKITD Evaluation Kit for the MAX17681 Isolated +7V or +5V Output Configuration
Evaluation Board9020MAX17681EVKITC Evaluation Kit for the MAX17681 Isolated +15V or +12V Output Configuration
Evaluation Board8751MAX17681EVKIT Evaluation Kit for MAX17681 Isolated ±15V or ±12V Output Configuration